The present invention relates generally to rechargeable batteries, and, more particularly to a battery charger for simultaneously charging a plurality of battery cells.
In the relatively recent past, an increasing number of battery operated devices, such as radios, children's toys, flashlights and the like are being powered by rechargeable secondary cells. Rechargeable secondary cells offer a particularly advantageous cost savings over primary cells (i.e., ordinary dry cell batteries) since the latter have a relatively short useful life, dissipating all their electrical energy and requiring repeated replacement during the life of the device powered thereby.
In view of the increasing use of rechargeable batteries, battery charging devices are needed which are relatively inexpensive to fabricate and are adapted to charge several battery cells simultaneously. Such charging devices are needed, for example, in stores where the batteries are sold to keep the batteries fully charged for immediate use by the consumer. In addition, these multi-cell charging devices will find substantial application in the home where the increasing uses of these batteries demands such facilities.
Multi-cell charging devices, such as the charging modules disclosed in U.S. Pat. No. 4,009,429 which is assigned to the same assignee as the present patent application, have been proposed for charging two or more rechargeable cells. Although such devices provide satisfactory results for many applications, they are capable of simultaneously charging a relatively small number of cells.
One prior art attempt at providing a charging apparatus for a varying number of battery cells is disclosed in U.S. Pat. No. 3,696,283 wherein a plurality of two-battery charging modules can be releasably coupled together. Although this apparatus may provide adequate results for some applications, it does suffer certain disadvantages. The apparatus is not formed as a convenient unitary device but, rather, requires several separate modular structures which must be stored together. It thereby involves substantial fabrication costs, particularly for the materials. In addition, without the power supply module, the other modules are useless.
Accordingly, it is an object of the present invention to provide a new and improved multiple-cell battery charger. It is another object of the present invention to provide a new and improved multiple-cell battery charger adapted to be made from relatively inexpensive component parts.
It is also an object of the present invention to provide a new and improved multiple-cell battery charger fabricated from parts which, except for the electronic components, can be inexpensively mass produced.
It is a further object of the present invention to provide a new and improved multiple-cell battery charger, wherein the terminals of batteries inserted into the charger are automatically positioned in proper registration with the electrical contacts of the charging conduit.
It is yet another object of the present invention to provide a new and improved multiple-cell battery charger, wherein the first cell placed therein for charging is the first cell to be removed.
It is an additional object of the present invention to provide a new and improved multiple-cell battery charger which includes relatively simple and inexpensive indicator means for indicating when a cell is being charged.
It is still another object of the present invention to provide a new and improved multiple-cell battery charger having a unitary structure capable of receiving a varying number of battery cells.
It is yet an additional object of the invention to provide a new and improved multiple-cell battery charger wherein the presence of a defective cell therein will not prevent other cells from being recharged.
Objects and advantages of the invention are set forth in part above and in part below. In addition, these and other objects and advantages of the invention will become apparent herefrom or may be appreciated by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims. Accordingly, the invention resides in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.